The Ultra Breathable 2-Stage starts with a firm, flat crib mattress for safety, then we add a breathable mattress pad to keep your baby cool and dry. The patented waterproof surface of the mattress protects the interior from urine, spit-up, and other messes, and its easy to wipe clean. Meanwhile, the breathable mattress pad maximizes airflow between the baby and mattress for a cool, comfortable sleep with less risk of overheating. The Ultra Breathable's intelligent organic design is free of flame retardant chemicals and other questionable materials. Our combination of organic, breathable, and practical makes the Ultra Breathable 2-Stage a healthier, safer crib mattress than conventional breathable designs.